Construction of this bicycle makes possible to considerably and very quickly decrease its overall dimensions and to adjust it easily for two persons.
The bicycles with the drive on the front wheel have been known for long time (SHIRE & BONESHAKER 1870, or DEKSTER 1869), and the functionality of the overall dimensions reduction have been realised in many ways.
In known bicycles, the functionality of folding is realised most often by use of additional constructional elements. The bicycle known from Polish application 17.344428 is, for example, fitted with additional joints, making it possible to “break” the bicycle in the locations of junctions of the frame beams and in the handlebar plane. Introduction of such additional elements is troublesome because it lengthens the time for preparation of the bicycle for driving, and increases its weight and cost.
A folding bicycle is known as well from Polish application P.354284. In this bicycle, a rear rocker is joined to the end of the frame through a telescopic suspension of the rear wheel. Front and rear wheels are joined to front and rear rockers, respectively. Telescopic elastic suspension of front wheel, rail suspension of rear wheel, the handlebar axle and the treadles with cranks are fitted with quick releases. The functionality of folding is realised in this bicycle also through the use of additional elements.
Also from Polish application P.292655 a bicycle is known with a rhomboidal frame cut along the shorter diagonal, where these cuts are subsequently removably joined with articulated locks. The bicycle is folded by releasing of the locks on the frame.
A bicycle with a rear drive is known from Polish application P.377279, where the axis of the handlebar fixed to the frame runs through the point of intersection of the front wheel with the floor, and the angle made by this axis with the floor equals about 70°.
To summarize, all known constructions of bicycles with the functionality of folding require usage of additional elements.